Data storage media density has significantly increased over the last several decades. Thin film recording head technology has advanced to keep up with increasing data storage media density through the advent of technologies such as giant magnetoresistive (GMR), tunneling magnetoresistive (TMR), or perpendicular magnetic recording (PMR). Each of these magnetic recording technologies may incorporate a magnetic shield as a component of the completed magnetic recording head system. As the various recording head technologies target smaller and smaller bit sizes, increased magnetic shield domain stabilization is required to reduce magnetic noise. One method of managing magnetic shield domain stability is to incorporate an anti-ferromagnetic material to bias the shield into a desired magnetic orientation, creating an antiparallel composite shield configuration. In such a configuration, the thin film recording sensor is surrounded by a soft bias material, and a pair of ferromagnetic layers separated by a spacer layer are deposited thereon, such that the upper ferromagnetic layer is magnetically pinned to the lower ferromagnetic layer, but separated by the spacer. In this shield configuration, as the spacer layer thickness is increased, magnetic coupling performance decreases, effectively limiting the spacer thickness. However, at very thin spacer thicknesses, shield stability decreases due to irregular grain growth in the ferromagnetic layers surrounding the spacer. The irregular growth increases with multiple anneals of the shield, and thus shield stability decreases with multiple anneals. This constraint requiring the spacer to be thicker to avoid shield instability, but thinner to maintain a strong antiparallel coupling performance, effectively limits the effectiveness of the currently available magnetic shields.
The figures are not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be understood that the invention can be practiced with modification and alteration, and that the disclosed technology be limited only by the claims and the equivalents thereof.